OpenShift Camel Component in a SwitchYard Project – An Overview

Posted: April 3rd, 2014 | Author: | Filed under: Technology | Tags: , , | 2 Comments »

Camel OpenShift SwitchYard LogoIn an earlier post, I introduced a custom Apache Camel component that can be used to manage the OpenShift platform. It allows for the invocation of operations that control key components of the OpenShift lifecycle such as displaying user metrics and managing applications. The operations and metrics generated from this component can be used in a variety of applications that leverage the Camel framework to solve business goals. Camel can be deployed to a variety of runtime environments ranging from servlet containers such as Tomcat, application servers such as JBoss , OSGi containers such as Karaf, or even self sufficient as a standalone application. To demonstrate the functionality of the OpenShift Camel component in a project, we will leverage SwitchYard and JBoss as the running environment within a sample project called camel-openshift-switchyard. SwitchYard is a services delivery framework for running and managing service-oriented applications. By running on SwitchYard, it will allow for the opportunity to cover both the OpenShift Camel component and developing and running applications using Switchyard. This post will provide an overview to the sample project including the steps necessary to configure and deploy either in your own environment or on the OpenShift platform. In subsequent posts, we will review the project in depth including how Camel can be integrated into a SwitchYard project and how to integrate the OpenShift Camel component in a project of your own.

The camel-openshift-switchyard project consists of a SwitchYard application and a basic web application that can be used to invoke services exposed by SwitchYard. The SwitchYard application contains two services: OpenShiftOperationsService and OpenShiftApplicationsStartupService. Each contains Camel routes utilizing the OpenShift Camel Component. The OpenShiftOperationsService invokes operations against a given users’ account such as retrieving the details of a given domain or applications within a domain. Meanwhile, the OpenShiftApplicationStartupService will attempt to start any Application associated to a user that is not currently started. A diagram depicting these services and the overall SwitchYard composite is shown below:

Camel OpenShift SwitchYard Composite

Both services contain a RestEasy binding to allow for external invocation via REST. The OpenShiftApplicationsStatup service also contains a timer binding which will initiate the service at the top of each hour based on a cron schedule. To take advantage of the scheduled service operation, the following two system properties must be configured either within the application itself or on application platform.

  • openshift.user – The login of the OpenShift user
  • openshift.password – The password on the account

Testing

Included in the project are a series of integration tests designed to validate the functionality of the application and to demonstrate the testing capabilities of SwitchYard applications. Injection of property values and invocation of Services and HTTP resources are some of the components demonstrated.

Building and Deploying

The project is hosted on GitHub and can be cloned into a local environment by running the following command:

git clone https://github.com/sabre1041/camel-openshift-switchyard.git

Prior to built or imported into an IDE, certain project dependencies must be configured. A core project dependency is the OpenShift Camel component which must be installed and available in the local Maven repository. Because this library is not part of any publicly available repository, initialization scripts for both Windows and Unix have been provided to configure the required dependencies. This script is found in the support folder of the project. Execute the init.sh or init.bat depending on your Operating System.

Next, build the project using Maven by running the following command:

mvn clean install

With the project now built, deploy the archive to Fuse Service Works or a JBoss container with SwitchYard installed. Once deployed, the application can be accessed by browsing to http://localhost:8080/camel-openshift-switchyard/

 Camel OpenShift SwitchYard Application

Deployment to OpenShift

The project has been configured to be seamlessly deployed to the OpenShift Platform. OpenShift provides the functionality to utilize custom cartridges which are not part of the core OpenShift platform to host applications. Since this project is built on SwitchYard, we will leverage a custom JBoss EAP 6 cartridge preconfigured with the SwitchYard runtime. The OpenShift Web interface provides the ability to specify a custom cartridge and existing source code during new application creation. However, due to the number of dependencies required by the SwitchYard platform, the project is unable to be built and deployed prior to the default application creation timeout. To get around this limitation, we will create the application using the OpenShift command line tools (RHC), merge the local OpenShift project with the camel-openshift-switchyard project hosted on GitHub, then finally push the application to OpenShift. Using the terminal in the location where the repository of the newly created application will be created on your local machine, issue the following command to create an application using the custom SwitchYard cartridge as the container.

rhc app create <app-name> "http://cartridge-switchyard.rhcloud.com/manifest/466c7020661420c4604e870802fe673244861a5a"

After the application was successfully created and the source code now available on your machine, change into the application directory:

cd <app-name>

First, add the GitHub hosted project as an upstream Git remote repository

git remote add upstream -m master https://github.com/sabre1041/camel-openshift-switchyard.git

Next, pull in the changes from the upstream repository

git pull -s recursive -X theirs upstream master

Finally push the changes to OpenShift

git push origin master

OpenShift will then handle obtaining the required dependencies, building and deploying the project. Once complete, the application can be viewed in a web browser. To determine the URL of an OpenShift application from the command line, execute the following command:

rhc app show <app-name>

You should be able to browse to the URL and utilize the application as you would on your local machine.

As mentioned previously, we will walk through the project in detail in a future post. This will allow for the demonstration of SwitchYard components and provide examples of how the OpenShift Camel component can be used in projects of your own.